As our sheepdog edges toward twilight, we have a decision to make

He lives his days in never-ending twilight now, his vision blurred and milky. His hind legs, which once were powerful enough to send him leaping over fences and galloping down a hill, tremble as he struggles to stand. His great heart murmurs a bit, in this twelfth year of his life, and he spends most of his time in a dozing sleep that we pray is peaceful. Sometimes he wanders into the dining room and stands, staring with blind eyes, as if he cannot remember where he is. And our hearts break a little more. But this thinner, infinitely more frail sheepdog is still our Rags, protector of our home and beloved elder of our family.

Recently Lee and I feared our dog would not live to the end of May. We came home from a two-night trip and found that he had missed us so desperately that he had gnawed and licked a large patch of skin on his haunch. He has always been anxious, in need of the predictable rhythms of our quiet household. I do all of my writing from home, and I always tell him when I'm leaving. “I'm going to the grocery store,” I'll call, loudly enough for his aging ears to hear me, as I ruffle the shaggy fur on his head. Or “I'll be at church for youth group with the kids.” He'll look up briefly at the sound of my voice, lick my hand, and then continue his nap. After the infection on his leg set in, though, he did not respond at all.

How do we know if it's time? I asked our compassionate veterinarian with tears in my eyes. At this point, there is no specific answer, she said. “Consider your dog's quality of life – and yours and your husband's. Does Rags still have a life that is happier than not? Are you and/or your husband losing sleep or becoming ill from worrying about him?” She wrote three prescriptions, for the infection, its side effects, and Rags' long-held anxiety issues. “See how he's feeling in a few weeks, after these meds have had a chance,” she suggested. “And know that we're here to help, whatever you decide.”

Lee has been giving him the prescribed three pills – each coated with Rags' favorite peanut butter – twice a day. I treated the infected patch with ointment until the redness and swelling subsided. Now our dog has rallied. We see his recovery in small details: a more alert lift of his head, an occasional bark at his longtime imaginary nemeses, the letter carrier and delivery truck driver. Hearing that warning bark again – “These are my sheep inside this house, and I will guard them from your dangerous garden catalogs and sinister boxes of new books!” – made me cry with gratitude. Rags also offers a muted but still joyous greeting every night when Lee comes home from work. The two of them used to spend a few minutes playing a vigorous round of tug-of-war with a big, red rubber bone. I'd hear fake growls (from both of them) and a final, triumphant “oomph” as Rags, always the victor, hoisted himself and his prized bone back onto his leather couch. Now their nighttime ritual involves only a lick on Lee's face and a gentle hug for the big dog. But it is enough.

Soon our family – including our daughter, son-in-law and three young grandchildren – will spend a week at a waterfront house on a lake – a house where dogs are strictly prohibited. When we planned the trip, we thought Rags would have drifted peacefully into a dog-friendly, heavenly garden by then. But he is feeling better now: Not great – with blindness, deafness and arthritis, he will never again feel great – but better. And Lee and I know our good dog would not survive a week in a kennel. He would not eat, and he would hurt himself badly again, from sadness and compulsive anxiety. He would not survive even if someone he knew came in to care for him, because we would not be with him.

“I can't see putting our dog to sleep just so we can go on vacation, Lee said, his voice breaking. He is not completely comfortable with our plan, but I am. Lee needs a week away. Time reading peacefully on a deck, overlooking the water. Exploring and entering the fantasy world of his grandchildren. I am a woman whose favorite place in all the wide world – and I have seen a bit of it – is her own home and garden. I will spend vacation week at home, with three cats and a sweet faced Old English sheepdog – my chief garden staffer emeritus – who deserves as many more twilights as he can manage. We will know when it's time, and that time is not yet here.